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LABORATORY EXPERIMENT № 10

STUDY OF THE EQUIPMENT FOR SAMPLING
THE FORMATION OIL

10.1. The objective of the experiment is: to study the structure
and the principle of operation of the sampler BS-3M (ПД-3М) for

raising up the subsurface samples of formation oil, to study flowing
and closed type samplers of other models and to study the procedure
of formation oil sampling.

10.2 Definitions

10.2.1 Classification of devices for sampling the downhole oil.
The structure of the sampler BS-3M (ПД-3М)

The properties of formation oil (density, viscosity, formation

volume factor, compressibility, the pressure of oil saturation by gas
and others) are determined experimentally by the results of laboratory
researches of the samples lifted from the well bottoms. For raising up

the downhole samples of oil out of the wells the special devices
(samplers) are used.
There are three types of samplers for taking oil downhole
samples: flowing, closed type and the samplers of combined type.

The flowing samplers are put down into the well with open
valves. The sampler of this type moving to the well bottom and
taking the sample into the chamber of the device is constantly

washed by upward oil flow. The inlet chamber of closed type sampler
while moving to the well bottom is closed (these devices take
the sample of oil into the chamber without beforehand flow of oil
through it). In this case the sample of oil is taken as a result of valve

opening and closing consequently.
By the method of control of valves operation downhole samplers
are divided into two groups: 1) the samplers with different relays and

2) the devices with the special gadgets requiring mechanical action
from the surface. The samplers of the first group are represented by
ones with different time relays: hydraulic, manometric, thermometric,

clockwork drive and power mechanisms. The samplers of the second

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